Recommissioning lathe size of hole to cut for belt

HI I am new to this forum and have not used a lathe since I was at school and had access to some fabulous machines.

I have obtained a Drummond and am in the process of re-designing a bench to hold it . This has been constructed from angle iron with two plates of 6mm. One on top and one on a shelf underneath for a motor drive.

I need to cut a slot in this top 6mm plate to allow the belt to pass through to the motor on the lower shelf. my pulley block is 100mm x50mm and is a standard three step pulley system. Can someone tell me please how much additional space I should add to the 100mm to allow for belt flex . I am using hoping to use a a chronos belt system. I am presuming that if the pulleys are 300mm located over the hole . I need to factor in that this will cope with tappers and enlarge the hole for this too . Does anyone have any useful help please

I have been told that about 1/2 deflection should be allowed for in the belts . This consider would it be better to have an X with the lines representing box slots with joined cut across tops or a regular larger rectangle be better?

Welcome to the wonderful world of Drummond lathes. What model do you have? (M-type here)

Are you using a counter shaft between the motor and the lathe pulleys? Are you talking about flat belt or V belt here?

Some pics of your set up would help. But basically, err on the side of a bigger hole rather than smaller. I would just cut a rectangular hole with maybe 25mm clearance all round the run of the belt.

Hi Hopper,

Yes its similar to a M series .

I am wondering if anyone has the original base and if they would be so kind to measure the cut out rectangle size on the cut in to the side and the width apart these cut ins are apart ?

I haven't worked out how to upload pictures here yet sorry.

Here is the frame work have made wanted it small so it would not take up so much space.

Have top plate mounted and lathe mounted . Have to work out the size of the belt holes am going for two i think as it will maintain some structure . I hope someone can tell me the size of the original cuts into the bed on the original stand to take this there is lots of pictures on http://www.lathes.co.uk/drummond/ but no dimensions of the slots to take the belts sadly.

This is as far as I have got . Cut some holes not sure they don't want to be bigger. Need motor next and a system to release and tension drive does anytone have any ideas please?

Will have to get motor next has anyone any experience with these please https://www.inverterdrive.com/group/Motors-AC/ac-Motor-250W-250-Watts-4Pole-4-pole-Foot-Mounting/

Edited By Martin Newbold on 11/01/2016 16:31:27

Ok have been quite making a motor plate and obtaining a motor these are now installed am looking for anyone who knows where I can obtain a small idler pulley with bearings in the UK as the smaller pulley on the bottom motor is allowing the belt to catch on the lathe. Is there any reason why I cant put the inverter in the door I want to make for the bottom.

http://www.model-engineer.co.uk/albums/member_photo.asp?a=39532&p=660215

As you can see the belt is good, but need to make a tensioner to bring the belt away from the lathe so it does not rub on the side and wear through the belt. Yes I know the gears will rotate and they need a cover Health and Safety

A very good and free idler pulley can be got from any repair garage- tensioner pullies for camshaft belts

I would check the speed you need, I imagine the motor you have is a 4 pole motor, 1450 rpm (aprox), I have a feeling that there should be a jack shaft in there to bring the speed down, probably about 3:1 reduction, someone with a Drummond might comment, you have done a good job.

Ian S C

Martin

Look at ... packed full of info for you ...

**LINK**

**LINK**

George.

Hi Ian , yes its three phase motor so will run from inverter to get speed down . I have not made bracket for inverter as have not bought it yet as need to locate or make a double pulley from billet so the belt clears the lathe chassis.The problems caused by the old treadle system having a larger pulley that took belt wide,

Mech yes the links are great., thank you I think it should end up running about 600 rpm not 1450 rpm as it will burn out bearings i think at higher speeds.

Gordon yes thank you have seen these on line but was thinking of getting one with double pulley so that if i do not have enough torque from current pulley combinations. I can step down without re fabricating. There is still much more to do I am painting at present the surface as rusting is a problem with this mild steel

Thank you so much for the help.,will keep you posted

Hi have been reading about Drummond reverse tumbler gears and there seems to be a project to make onee on an old youtube group which is not accessible to me can someone please provide the details which used to be there please

Edited By Martin Newbold on 19/03/2016 18:00:18

Martin, I think you probably mean the Yahoo Drummond group, rather than a Youtube group. Just looked on the Yahoo group files page and while there is a folder for the tumbler details the drawings of the individual parts aren't there any more. There is another folder in the files section with a 3d rendering of the tumbler mechanism, but no dimensions. You'd be better off joining the Yahoo Drummond group (if you haven't already) and asking the moderator if the details of the tumbler are still available and if so could he please put them back in the groups file section.

Hi Kieth , thanks for the reply yes i do mean the Yahoo group but have id but wont let me view it . I think its only an idler gear anyway am after a reverse tumbler for my recomissioned lathe someone must have one of these for a M series Drummond they are not using thats collecting dust . Its am odd looking this or photographs of one dismantled so perhaps it could be made . Would love to have the opportunity to buy it as i intend on using my lather properly

M series tumbler

What am after is just the piece which is bolted on like this, please or just some photographs or plans with it taken apart, thank you for looking

Edited By Martin Newbold on 20/03/2016 11:51:39

Martin

Just sent you a PM, please check your "Inbox" on this forum.

Keith

I just bought some covers from a Myford a bit of the front one cut down and considering if I can make brackets to cover front gears with them . Am going to buy inverter soon have been looking at ABB has anyone used them possibly the ABB ACS150 before please?